JP2019218960A - Excess flow prevention valve and excess flow prevention valve inspection device - Google Patents

Abstract

To provide an excess flow prevention valve which enables operation inspection of the excess flow prevention valve to be carried out in a short time without needing waste water treatment of a plant regardless of the time, and to provide an excess flow prevention valve inspection device.SOLUTION: A permanent magnet poppet valve 4 and a permanent magnet 8 are disposed in a hollow valve shaft 5 of an excess flow prevention valve 100. A direct current power source 9 is driven by a drive part 15 based on an instruction of an instruction part 16, and the permanent magnet poppet valve 4 is moved by an operation testing coil 10 to move a valve body 2. A detector 11 detects movement of the valve body 2 to enable operation inspection of the excessive flow prevention valve 100 to be performed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an overflow prevention valve for shutting off an overflow in a pipe and an inspection device therefor.

  In general, the instrumentation pipe connected to the pressure vessel of a nuclear power plant, etc., should be installed on the upstream side of the instrumentation It has an instrumentation piping configuration in which an overflow prevention valve is attached.

  This overflow prevention valve is schematically configured so that a poppet valve fixed on the upstream side by a valve body and a compression coil spring provided on the valve body can move to the downstream side according to a differential pressure between the upstream and downstream sides. .

  Before the normal operation of the plant, the flow of the fluid inside the instrumentation pipe is actually created, and the overflow prevention valve is operated to check whether the overflow prevention valve is sound. In this case, it is necessary to generate a differential pressure upstream and downstream of the overflow prevention valve in order to artificially confirm the operation. At this time, it is necessary to drain a high dose of water in the pressure vessel.

  In addition, due to the characteristic that the pressure in the pressure vessel needs to be a certain pressure or more, these operation inspection methods require that the overflow prevention valve be used only before the end of the periodic inspection performed during the shutdown period of a plant such as a nuclear power plant. Operation check cannot be performed.

  As a result, the inspection period of the overflow prevention valve is limited, and if there is a problem with the overflow prevention valve during operation inspection, the regular inspection period of the plant such as a nuclear power plant can be extended immediately before the end. There is also.

  For this reason, in the technology described in Patent Document 1, a portable vacuum pump line is connected downstream of the overflow prevention valve, and a system such as a nuclear power plant is sucked out by sucking out the fluid inside the instrumentation piping. During the stop period, the operation of the overflow prevention valve was checked regardless of the timing.

JP 2006-226947 A

  However, the above-mentioned prior art does not solve the necessity of drainage treatment of the reactor water filled in the instrumentation piping in order to check the overflow prevention valve.

  In addition, the portable vacuum pump line equipment is complicated in its configuration and requires a large number of man-hours for inspection work.

  Therefore, in the prior art, the check of the overflow prevention valve must be performed during the stop period of the plant, and much time and labor is required.

  The present invention has been made in view of the above points, and has as its object to check the operation of an overflow prevention valve at any time without the need for wastewater treatment of a plant, and to perform the inspection in a short time. An object of the present invention is to realize a flow check valve and an overflow check valve inspection device.

  The present invention is configured as follows to achieve the above object.

  In the overflow prevention valve, a valve body, a valve stem movably disposed inside the valve body, and a valve seat disposed at one end of the valve stem and seated on and separated from a valve seat formed on the valve body. A valve element, an elastic member that presses the valve element in a direction away from the valve seat, a permanent magnet poppet valve disposed at the other end of the valve stem, and a valve stem between the valve element and the permanent magnet poppet valve. And a permanent magnet disposed.

  In an overflow check valve checking device for checking an overflow check valve, an operation test coil arranged to surround the periphery of a permanent magnet poppet valve, a current supply unit for supplying a current to the operation test coil, and a permanent magnet And a detector for detecting a current generated in the operation detecting coil, which is disposed so as to surround the periphery of the operation detecting coil.

  Further, in the overflow check valve checking device for checking the overflow check valve, an operation test coil disposed so as to surround the periphery of the permanent magnet poppet valve, a current supply unit that supplies current to the operation test coil, An operation detection coil arranged to surround the periphery of the permanent magnet, a detector for detecting a current generated in the operation detection coil, and a primary coil and a secondary coil arranged to surround the magnetic body. A differential transformer having the same and a value diagnostic unit for transmitting a value of a current flowing through the differential transformer and a value of a current supplied from the current supply unit to the operation test coil, and for predicting deterioration of the overflow prevention valve.

  Further, in the overflow check valve checking device for checking the overflow check valve, an operation test coil disposed so as to surround the periphery of the permanent magnet poppet valve, a current supply unit that supplies current to the operation test coil, An operation detection coil arranged to surround the periphery of the permanent magnet, a detector for detecting a current generated in the operation detection coil, and an interval for measuring an interval between a valve body and a valve seat formed on the valve body. An output signal of the measurement sensor and a value of a current flowing from the current supply unit to the operation test coil are transmitted, and a sign diagnosis unit that indicates deterioration of the overflow prevention valve is provided.

  Advantageous Effects of Invention According to the present invention, an overflow prevention valve and an overflow prevention valve inspection device that can perform operation inspection of an overflow prevention valve at any time without requiring wastewater treatment of a plant and can be executed in a short time are realized. be able to.

FIG. 1 is a diagram illustrating a schematic configuration of an overflow prevention valve and an overflow prevention valve inspection device according to a first embodiment of the present invention. FIG. 4 is an operation explanatory diagram of the overflow prevention valve and the overflow prevention valve inspection device according to the first embodiment. It is a schematic structure figure of an overflow prevention valve and an overflow prevention valve inspection device by Example 2 of the present invention. It is a schematic structure figure of an overflow prevention valve and an overflow prevention valve inspection device by Example 3 of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each of the drawings, the same reference numerals are used for the same components.

(Example 1)
FIG. 1 is a diagram showing a schematic configuration of an overflow check valve 100 and an overflow check valve inspection device according to a first embodiment of the present invention.

  As shown in FIG. 1, an overflow prevention valve 100 according to the first embodiment includes a valve body 2, a compression coil spring (compression member) 3, a permanent magnet poppet valve 4, and a hollow valve stem 5. The coil spring 3, the permanent magnet poppet valve 4, and the hollow valve stem 5 are movably disposed inside the hollow valve body 1.

  The valve element 2 is arranged at one end of the valve stem 5, and the permanent magnet poppet valve 4 is arranged at the other end of the valve stem 5.

  An instrumentation pipe 18 is mounted on the upstream side of the fluid passing through the valve body 1 (the other end of the valve rod 5), and an instrumentation pipe 19 is provided on the downstream side of the fluid (one end of the valve rod 5). Is installed.

  The upstream instrumentation pipe 18 is connected to, for example, a reactor pressure vessel, and the downstream instrumentation pipe 19 is connected to a pressure gauge, a differential pressure gauge, or the like.

  The hollow valve stem 5 is made of a non-magnetic material, and has a permanent magnet 8 disposed therein. The permanent magnet 8 is arranged between the permanent magnet poppet valve 4 of the valve stem 5 and the valve body 2, and the operation detecting coil 12 is arranged on the outer periphery of the valve body 1 so as to surround the periphery of the permanent magnet 8. I have.

  The detector 11 is connected to the motion detection coil 12. The detector 11 detects a current generated in the operation detection coil 12 when the permanent magnet 8 moves on the inner peripheral side of the operation detection coil 12. The detector 11 can be configured to generate light or sound when the permanent magnet 8 moves.

  An operation test coil 10 is arranged on the outer periphery of the valve body 1 so as to surround the periphery of the permanent magnet poppet valve 4. The operation test coil 10 is connected to the DC power supply 9.

  As shown, the DC power supply 9 includes a rectifying element, an AC power supply, a capacitor, and an ammeter.

  The DC power supply 9 is driven according to a drive signal from the drive unit 15. The drive unit 15 drives the DC power supply 9 according to a command from the command unit 16 and supplies a current to the operation test coil 10. Thereby, the permanent magnet poppet valve 4 moves, and the valve body 2 also moves.

  The operation detection coil 12, the detector 11, the operation test coil 10, the DC power supply 9, the drive unit 15, and the command unit 16 constitute an overflow prevention valve inspection device.

  Normally, the valve body 2 is pressed in a direction away from the valve seat 1a formed on the valve body 1 by the reaction force of the compression coil spring 3, and its position is fixed on the upstream side, and the internal flow of the fluid is measured on the upstream side. It passes from the instrumentation piping 18 to the instrumentation piping 19 downstream.

  When a differential pressure is generated upstream and downstream of the overflow prevention valve 100 due to breakage of the instrumentation pipe 19 on the downstream side or the like, the compression coil spring 3 moves to the downstream side of the overflow prevention valve 100 due to the dynamic water pressure applied to the valve body 2. The valve body 2 is seated on a valve seat 1a formed on the valve body 1, and the overflow prevention valve 100 is closed.

  At this time, the detector 11 electrically detects that the overflow prevention valve 100 has been operated because the permanent magnet 8 inserted into the hollow valve stem 5 moves in the operation detecting coil 12. it can.

  FIG. 2 is a diagram for explaining the operation of the overflow prevention valve 100 and the operation of the overflow prevention valve inspection device during the operation check of the overflow prevention valve 100 according to the first embodiment. However, in FIG. 2, the drive unit 15 and the command unit 16 shown in FIG. 1 are omitted for simplification of the drawing.

  In FIG. 2, when the operator instructs an inspection command using the command unit 16, the driving unit 15 drives the DC power supply 9. Thereby, the operation test coil 10 is energized, the permanent magnet poppet valve 4 is moved by electromagnetic force, the valve body 2 is moved and seated on the valve seat 1a, and the overflow prevention valve 1 is closed. Can be. That is, even in a state where no differential pressure is generated upstream and downstream of the overflow prevention valve 100, the valve body 2 can be moved and the overflow prevention valve 1 can be closed.

  When the valve body 2 operates normally, a part of the permanent magnet 8 is not surrounded by the operation detecting coil 12 as shown in FIG. The permanent magnet 8 moves so that the state is surrounded by the operation detection coil 12. The movement of the permanent magnet 8 is detected by the detector 1 and generates light or sound, so that it can be determined that the overflow prevention valve 100 is normal.

  When the valve body 2 does not operate normally, the detector 1 does not detect that the permanent magnet 8 has moved, so that no light or sound is generated. Thereby, it can be determined that the overflow prevention valve 100 is not normal.

  The detector 11 is configured to receive a command from the command unit 16 and to notify an abnormality (for example, display in red) if the current is not detected within a predetermined time from that time. However, if the current is detected within a predetermined time, it may be configured to notify that the current is normal (for example, display in blue).

  In addition, since the operation check at the time of the inspection of the overflow prevention valve 100 can be completed in about several tens of seconds, the inspection operation can be performed without stopping the normal operation of the plant such as the nuclear power plant.

  As described above, according to the first embodiment of the present invention, the valve body 2 can be moved by the operation test coil 10 based on the command of the command unit 16, and the movement of the valve body 2 is detected by the detector 11. The operation check of the overflow prevention valve 100 can be performed at any time without requiring the wastewater treatment of the plant, and the overflow prevention valve inspection device can be performed in a short time. Can be realized.

  Further, since the permanent magnet poppet valve 4 and the permanent magnet 8 are arranged on the hollow valve rod 5 of the overflow check valve 100, the overflow check valve inspection device does not require drainage treatment of the plant. It is possible to realize an overflow prevention valve that can be performed at any time and can be executed in a short time.

  For example, since a large number of overflow prevention valves are present in a nuclear power plant, according to the first embodiment of the present invention, the inspection of the overflow prevention valve 100 is performed by stopping the operation of a plant such as a nuclear power plant. And can be implemented in a short time.

(Example 2)
Next, a second embodiment of the present invention will be described.

  FIG. 3 is a schematic configuration diagram of an overflow prevention valve 101 and an overflow prevention valve inspection device according to a second embodiment of the present invention.

  The difference between the first embodiment and the second embodiment is that, in the second embodiment, the magnetic body 6 is disposed between the permanent magnet poppet valve 4 of the hollow valve stem 5 and the permanent magnet 8, and surrounds the magnetic body 6. The difference is that the differential transformer 13 having the primary coil 21 and the secondary coils 20a and 20b is arranged, and the sign diagnosis unit 14 is further arranged.

  Other configurations are the same as those of the first embodiment and the second embodiment, so that illustration and detailed description are omitted.

  The overflow prevention valve 101 according to the second embodiment includes a valve body 1, a valve body 2, a compression coil spring 3, a permanent magnet poppet valve 4, a hollow valve rod 5, and a magnetic material 6 at a substantially central portion of the hollow valve rod 5. A magnet 8 is arranged.

  The overflow prevention valve inspection device according to the second embodiment includes an operation detection coil 12, a detector 11, an operation test coil 10, a DC power supply 9, a driving unit 15, a command unit 16, The transformer 13 and the sign diagnosis unit 14 constitute an overflow prevention valve inspection device.

  In FIG. 3, when an inspection command is instructed from the command unit 16, the drive unit 15 controls the operation of the DC power supply 9 to continuously change the current flowing from the DC power supply 9 to the operating point test coil 10 from zero current. To be inclined.

  The value of the current supplied from the DC power supply 9 to the operation test coil 10 (the value of the current supplied from the current supply unit to the operation test coil 10) is transmitted from the DC power supply 9 to the sign diagnosis unit 14.

  Further, the value of the current flowing through the differential transformer 13 is also transmitted from the differential transformer 13 to the sign diagnosis unit 14.

  The predictive diagnosis unit 14 differentiates a changing current value transmitted from the DC power supply 9. Further, the predictive diagnosis unit 14 differentiates the current value transmitted from the differential transformer 13. The change in the current value transmitted from the differential transformer 13 corresponds to the moving speed of the magnetic body 6, that is, the changing speed of the main valve opening of the valve body 2. By comparing the differentiated value with the value obtained by differentiating the current value transmitted from the differential transformer 13, deterioration (set) of the compression coil spring 3 of the overflow prevention valve 101, sludge and the like are reduced. Can be predicted, and deterioration of the overflow prevention valve 101 can be predicted.

  In other words, the proportional relationship between the value obtained by differentiating the current value transmitted from the DC power supply 9 and the value obtained by differentiating the current value transmitted from the differential transformer 13 in the overflow prevention valve 101 in a state in which it has not deteriorated is predicted. A value obtained by differentiating a current value transmitted from the DC power supply 9 and a value obtained by differentiating the current value transmitted from the differential transformer 13, which is stored in the diagnostic unit 14 and detected at the time of checking the overflow prevention valve 101, is stored. By comparing with the proportional relationship, the main valve opening (valve opening of the valve body 2) is continuously measured, the valve opening speed is measured, and the deterioration state of the overflow prevention valve 101 is diagnosed. , Can be a sign.

  If the predictive diagnosis unit 14 determines from the result of the comparison that the difference between the proportionalities of the two exceeds a predetermined value, the predictive diagnosis unit 14 notifies the operator of the deterioration of the overflow prevention valve 101 by light emission or sound.

  When the overflow prevention valve 101 does not operate despite the operation command being issued by the command unit 16, the failure of the overflow prevention valve 101 can be detected by the detector 11 as in the first embodiment. .

  According to the second embodiment of the present invention, the same effect as that of the first embodiment can be obtained. In addition, the overflow prevention valve 101 can diagnose a deterioration state before a failure occurs, and a new overflow prevention can be performed. The valve 101 can be replaced.

  In the case where the second embodiment of the present invention is not applied, it is necessary to check the deterioration of the overflow prevention valve 101 by disassembling the overflow prevention valve 101 before the failure occurs. Since a large number of overflow check valves are present in a plant such as a nuclear power plant, when the second embodiment of the present invention is not applied, the disassembly check of the overflow check valve requires a great amount of time and labor. is there.

  According to the second embodiment of the present invention, it is possible to check the deterioration of the overflow prevention valve 101 without disassembling the overflow prevention valve 101, and to quickly check the overflow prevention valve 101 before a failure occurs. It becomes possible to exchange.

  In the example described above, the value obtained by differentiating the current value transmitted from the DC power supply 9 and the value obtained by differentiating the current value transmitted from the differential transformer 13 in the overflow prevention valve 101 in the undegraded state. Is stored in the predictive diagnosis unit 14, and a value obtained by differentiating a current value transmitted from the DC power supply 9 detected at the time of inspection of the overflow prevention valve 101 and a current value transmitted from the differential transformer 13 are Although the configuration is such that the proportional relationship with the differentiated value is compared, other configurations are also possible.

  As an example, the current value transmitted from the DC power supply 9 is used as a determination to start measuring the current value transmitted from the differential transformer 13, and only the current value transmitted from the differential transformer 13 is differentiated to obtain a valve body. 2, the change rate of the valve opening degree is calculated, and the calculated change rate of the valve opening degree is compared with the change rate of the valve opening degree of the healthy overflow prevention valve 101 to diagnose the deterioration of the overflow prevention valve 101. It is also possible to configure.

(Example 3)
Next, a third embodiment of the present invention will be described.

  FIG. 4 is a schematic configuration diagram of an overflow prevention valve 102 and an overflow prevention valve inspection device according to a third embodiment of the present invention.

  The difference between the second embodiment and the third embodiment is that, in the third embodiment, the magnetic material is not disposed substantially at the center of the hollow valve stem 5, and the primary coil 21 and the secondary coils 20a and 20b are connected to each other. No differential transformer 1 is provided, and an interval measuring sensor 22 for measuring the interval between the valve body 2 and the valve seat 1a is disposed on the valve seat 1a of the valve body 2 of the valve body 1 to measure the interval. An output from the sensor 22 (a signal indicating the distance between the valve seat 1 a and the interval sensor 22) is transmitted to the predictive diagnosis unit 14.

  Other configurations are the same as those of the second embodiment and the third embodiment, so that illustration and detailed description are omitted.

  The overflow prevention valve 102 according to the third embodiment includes a valve body 1, a valve body 2, a compression coil spring 3, a permanent magnet poppet valve 4, a hollow valve stem 5, and a permanent magnet 8.

  The overflow prevention valve inspection device according to the third embodiment includes an operation detection coil 12, a detector 11, an operation test coil 10, a DC power supply 9, a driving unit 15, a command unit 16, a predictive diagnosis, The section 14 and the interval measurement sensor 22 constitute an overflow prevention valve inspection device.

  In FIG. 4, when an inspection command is instructed from the command unit 16, the drive unit 15 controls the operation of the DC power supply 9 to continuously change the current flowing from the DC power supply 9 to the operation test coil 10 from zero current. Raise in an inclined manner.

  The value of the current supplied from the DC power supply 9 to the operation test coil 10 is transmitted from the DC power supply 9 to the sign diagnosis unit 14.

  Further, an output signal from the interval measurement sensor 22 is also transmitted to the sign diagnosis unit 14.

  The predictive diagnosis unit 14 differentiates a changing current value transmitted from the DC power supply 9.

  Further, the predictive diagnosis unit 14 differentiates the interval value indicated by the signal transmitted from the interval measurement sensor 22. Since the change in the interval value transmitted from the interval measurement sensor 22 is a change in the moving speed of the valve body 2, the value obtained by differentiating the current value transmitted from the DC power supply 9 and the signal transmitted from the interval sensor 22 are determined. Is compared with a value obtained by differentiating the overflow prevention valve 102, it is possible to predict that the compression coil spring 3 of the overflow prevention valve 102 has deteriorated (set) or that sludge or the like exists in the overflow prevention valve 102. The deterioration of 102 can be predicted.

  In other words, the proportional relationship between the value obtained by differentiating the current value transmitted from the DC power supply 9 and the value obtained by differentiating the value of the signal transmitted from the interval measurement sensor 22 in the overflow prevention valve 102 in the undegraded state. The differential value of the current value transmitted from the DC power supply 9 and the value of the signal transmitted from the interval measurement sensor 22 detected at the time of inspection of the overflow prevention valve 102 are differentiated. By comparing the proportional relationship with the value, it is possible to diagnose and predict the deterioration state of the overflow prevention valve 102.

  If the predictive diagnosis unit 14 determines from the result of the comparison that the difference between the two is greater than or equal to a certain value, the predictive diagnosis unit 14 notifies the operator of the deterioration of the overflow prevention valve 102 by light emission or sound.

  If the overflow prevention valve 102 does not operate even though the operation command is issued by the command unit 16, the failure of the overflow prevention valve 102 is detected by the detector 11 as in the first and second embodiments. can do.

  According to the third embodiment of the present invention, the same effect as that of the second embodiment can be obtained. In addition, the deterioration state of the overflow prevention valve 102 can be diagnosed before a failure occurs. The valve 102 can be replaced.

  As the interval measurement sensor 22, for example, a capacitance type sensor that measures the capacitance between the valve body 2 and the valve seat 1a, an eddy current displacement sensor, or the like can be used.

  Note that the present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described above.

  In addition, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of one embodiment can be added to the configuration of another embodiment.

  Further, for a part of the configuration of each embodiment, it is possible to add, delete, or replace another configuration.

  For example, the DC power supply 9 applied during the main valve operation check needs to be continuously increased from zero current, and the power supply is a three-phase AC power supply connected to the three-phase full-wave rectifier circuit shown in FIG. Instead, the present invention may be realized by a battery or the like to which a variable resistor is connected.

  That is, the DC power supply 9 can be a three-phase AC power supply or a variable current source using a battery or the like to which a variable resistor is connected.

  The compression coil spring 3 can use not only a coil spring but also a leaf spring or another elastic member, and can be defined as an elastic member including these members.

  In the above-described embodiment, the DC power supply 9 is configured to operate by the driving unit 15 that operates according to the command from the command unit 16. It is also possible to configure the DC power supply 9 to operate periodically. Therefore, the DC power supply 9, the drive unit 15, and the command unit 16 are defined as a current supply unit. There are examples in which the current supply unit includes the command unit 16 and examples in which the current supply unit does not include the command unit 16.

  DESCRIPTION OF SYMBOLS 1 ... Valve main body, 2 ... Valve body, 3 ... Compression coil spring, 4 ... Permanent magnet poppet valve, 5 ... Hollow valve stem, 6 ... Magnetic body, 7 ... Part of valve stem, 8: permanent magnet, 9: DC current source, 10: operation test coil, 11: detector, 12: operation detection coil, 13 ... Differential transformer, 14 ... Sign diagnosis unit, 15 ... Drive unit, 16 ... Command unit, 18, 19 ... Instrumentation piping, 20a, 20b ... Secondary coil, 21 ... Primary coil, 100, 101, 102 ... Overflow check valve

Claims (7)

A valve body,
A valve stem movably disposed inside the valve body,
A valve body disposed at one end of the valve stem, seated on a valve seat formed on the valve body and separated from the valve seat,
An elastic member that presses the valve body in a direction away from the valve seat,
A permanent magnet poppet valve disposed at the other end of the valve stem;
A permanent magnet disposed between the valve body and the permanent magnet poppet valve of the valve stem;
An overflow prevention valve, comprising: The overflow prevention valve according to claim 1,
An overflow prevention valve, further comprising a magnetic body of the valve stem disposed between the permanent magnet poppet valve and the permanent magnet. An overflow check valve inspection device for checking an overflow check valve according to claim 1,
An operation test coil arranged to surround the periphery of the permanent magnet poppet valve;
A current supply unit for supplying a current to the operation test coil;
An operation detection coil arranged to surround the periphery of the permanent magnet,
A detector for detecting a current generated in the operation detection coil,
An overflow check valve inspection device, comprising: An overflow check valve checking device for checking an overflow check valve according to claim 2,
An operation test coil arranged to surround the periphery of the permanent magnet poppet valve;
A current supply unit for supplying a current to the operation test coil;
An operation detection coil arranged to surround the periphery of the permanent magnet,
A detector for detecting a current generated in the operation detection coil,
A differential transformer having a primary coil and a secondary coil arranged to surround the periphery of the magnetic body,
A sign diagnosis unit that transmits a value of a current flowing through the differential transformer and a value of a current supplied from the current supply unit to the operation test coil, and predicts deterioration of the overflow prevention valve,
An overflow check valve inspection device, comprising: An overflow check valve inspection device for checking an overflow check valve according to claim 1,
An operation test coil arranged to surround the periphery of the permanent magnet poppet valve;
A current supply unit for supplying a current to the operation test coil;
An operation detection coil arranged to surround the periphery of the permanent magnet,
A detector for detecting a current generated in the operation detection coil,
An interval measurement sensor that measures an interval between the valve body and a valve seat formed on the valve body,
An output signal of the interval sensor and a value of a current flowing from the current supply unit to the operation test coil are transmitted, and a sign diagnosis unit that indicates deterioration of the overflow prevention valve,
An overflow check valve inspection device, comprising: The overflow prevention valve inspection device according to any one of claims 3, 4, and 5,
The current supply unit includes a variable current source, a driving unit that drives the variable current source, and a command unit that commands the driving unit to drive the variable current source. Valve inspection device. The overflow prevention valve inspection device according to claim 6,
The variable flow current source is a DC power supply, and the overflow prevention valve inspection device is characterized in that:

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